2008 YZ450-White Oil Residue From Breather Tube?

The History:

I just washed my bike and changed the oil and filter on my 2008 450 at 38.0 hours with Castro GTX synthetic 4 stroke oil. I ride vet. intermediate and don't bounce the bike off the rev-limiter. I don't abuse my bike by any means.

The Scenario:

After I rode the MX track for 1.9 hours today, I noticed a few drips of white oily residue on the floor of my trailer. I inspected the drips and found they were coming from the breather tube. The bike dripped a few more drops and then stopped. The fluid was white in color, had an oily feel and had a faint smell of gasoline. I checked the oil in the case and it was perfect in color, feel, and smell. It didn't resemble the drops on the floor by any means.

The Question:

What's going on here? I'm checking my valves again this week since I'm at the 40 hour mark. 10 hours ago they were still in factory spec. Any ideas on what's happening?


I see you are in Idaho---pretty cold there right now---could that possibly be some condensation mixed with the usual bit of oil blowby from the breather tube?

45 degrees today with light rain. I've ridden in much colder and wetter this winter and have never seen any white oily discharge from the breather tube. Thus my post. I just want to see if I've got a problem on my hands or if this is a normal 450 thing.

If your oil is clear, it's just condensation.

occasionally i ride a trail that has a lot of standing water and creek crossings (some are pretty deep) and have noticed the same thing. in my case its simply water going up the vent tube and mixing with the oil in the lower part of the tube (i know, i checked the top end out the first time it happened). i rerouted the tube to help prevent further incedents.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By faizakhtar125
      Hey guys I just bought a bike last night. So the seller said the bike will turn on but then die. We didn't try it because it was really late at night and it was raining (seat was wet). But he said if you bump start it, it will turn on and ride. So what do you think the problem is? I just want to make sure it runs... I probably won't be able to bump start it till Saturday (rain)... It's a four stroke, and I know absolutely nothing about them. Thanks.
    • By dpenn1
      I could use some feedback, My son is getting into off road riding so I have starting getting back into it as well.  We mostly do trail riding but did some MX track riding last year and he loved it andso did I.  I have a 2003 TTR 225, it's nice that it has an electric start but the suspension is too soft and it doesn't have enough power for my liking.  When I was riding the MX track I was having issues bottoming out on the larger jumps.  I want to change to a more off-road capable bike.   I won't ride it much and don't want to spend a lot of money, I think I prefer a 2 stroke, when I was younger, in 1990, I raced an 89 RM250 and loved it.  I am looking at a 96 RMX 250  and a 98 YZ400F, both bikes look to be in good condition and around a thousand dollars.  I like the RMX because I think kicking a 2 stroke 250 should be easier than a 4 stroke 400 and the simplicity of the 2 stroke engine.  The 400 sounds good because of the low end torque I assume it has but the cost of rebuilding the 4 stroke if needed worries me and I have heard they are hard to start. Should the RMX be decent for an occasional trip to an MX park?  Any thoughts on these two bikes? 
    • By yz480doinwork
      Brand new, still in the packaging Lexx end cap fits the stock muffler of 2006 & 2007 YZ450f and 06-13 YZ250f. Comes with a forest service approved spark arrestor and two different size tips. Don't spend hundreds of dollars on a slip on, this tip can be quiet and forest legal or loud and make power! Also a note for WR450 guys: get this tip and find a used 06/07 YZ muffler, fits directly on 09-15 WR450. $80 shipped free to the lower 48. PM, call or text 406-223-8789
    • By Woody Oakson
      So I have a 2008 yz450f and I would like to add some LED lights to it to make it street legal. Mainly just a headlight and a tail light and turn signals if I need to (which where I live hand signals work).
      So where I need help is getting power from the stator to a battery. Wiring from a battery to anything else I got and understand and don't need help with (but recommendations are welcome). So my questions are.
      What type of power is coming from the stator. AC or DC? Will I need a regulator or rectifier? How do I wire something from the stator to charge a battery? What would that wiring look like? Would this stator http://www.rickystator.com/product/stators/yamaha/yamaha-yz450f-35-watt-lighting-stator-assembly-06-09 work? Anything else I should know? Any help would be appreciated. Thank you.